Question

Case 2

Martin Smith is a 57 year old sales manager who is significantly overweight. Despite his physician’s urging, Mr. Smith continued to eat a rich diet that included red meat and high-calorie desserts. He also enjoyed unwinding with a few beers each evening. He had occasional angina that was relieved by nitroglycerin (1 tablet, 0.4 mg, sublingual).

On the night of February 3, 2017, Mr. Smith went to bed early because he wasn’t feeling well. He woke up at 2 am with crushing pressure in his chest and pain radiating down his left arm. He took 1 tablet of nitroglycerin, which did not relieve the pain. Mr. Smith’s wife called 911 and two EMTs promptly arrived. They found Mr. Smith alert and oriented. His skin was pale, cool, and diaphoretic. His pulse was 118, irregular, weak and thready. His respiration was 28, regular rhythm, shallow, labored, with rales upon inspiration. His blood pressure was 156/92. Mr. Smith complained of nausea, and dyspnea when supine. The EMTs placed him on oxygen, and assisted him in taking another nitroglycerin. Paramedics arrived on the scene, performed an ECG and recognized an ST elevation myocardial infarction (STEMI) The EMTs promptly transported Mr. Smith to the nearest STEMI receiving center.

Mr. Smith’s serum levels of creatine phosphokinase and lactate dehydrogenase were high. Pulmonary capillary wedge pressure was 30 mmHg (normal 5 mmHg), and his ejection fraction was 0.35 (normal 0.55).

Mr. Smith was treated with a thrombolytic agent, digitalis, and furosemide. After 7 days in the hospital, he was sent home on a strict low Na+ diet.

Questions:

5. Discuss the physiological reason for each of the signs that the EMTs assessed (skin, pulse, respiration, blood pressure).

6. Discuss the pulmonary edema in this case using Starlings forces. Why did it develop? Why is it so dangerous? Why did Mr. Smith have dyspnea, particularly when supine?

7. Discuss the physiological reason for the test results performed at the STEMI center (creatine phosphokinase, lactate dehydrogenase, pulmonary capillary wedge pressure, ejection fraction).

8. Discuss the rationale for each treatment (thrombolytic agent, digitalis, furosemide, low Na+ diet).

Case 3

Brenda Williams is a 73 year old retired seamstress. She is a chain smoker. When her employer announced that smoking would no longer be allowed in the store, she retired. Since her retirement, Mrs. Williams has not been feeling well. She fatigues easily, even with light exertion. She has dyspnea and recently has begun to sleep on two pillows.

Early this morning, Mrs. Williams woke up with severe dyspnea and called 911. EMTs found her alert and oriented, and in significant respiratory distress. Her skin was pale with cyanotic nail beds, cool, and moist. Her pulse was 112, regular, and strong. Her respirations were 26, regular rhythm and depth, and labored. She had an increased anteroposterior chest diameter and audible expiratory wheezes. Blood pressure was 128/85. SpO2 was 83%. They noted pitting edema of her ankles. She denied chest pain. They put her on oxygen and transported her to the emergency room.

Her physician noted a long expiratory phase in her breathing. Based on this observation, her history, and her vital signs, he ordered the following tests:

Pulmonary function tests:
Vorced Expiratory Capacity (FEV1): reduced Residual volume: increased
Laboratory values:
Hemoglobin 14.5 g/dL (normal 12-15 g/dL) Arterial PO2 48 mmHg (normal 100 mmHg) O2 saturation 86% (normal 98-100%)
Arterial PCO2 69 mmHg (normal 40 mmHg) HCO3-: 34 mEq/L (normal 24 mEg/L)
pH: 7.31

The physician concludes that Mrs. Williams has a combination of emphysema and chronic bronchitis, called chronic obstructive pulmonary disease.

Questions:

9. Explain why Mrs. Williams was in respiratory distress.

10.Explain the physiological reasons for the signs that the EMTs assessed (skin, pulse, respiration, anteroposterior chest diameter, blood pressure, pulse oximetry, and pitting edema).

11.Explain the physiological reasons for each of her test results (both pulmonary and laboratory).

12.Which acid-base disorder does she have? What is the cause? What is the compensation? How does this alter oxygen delivery to the tissues?

13.Explain why her hemoglobin was normal but her SpO2 and her arterial PO2 were low. Should these tests have similar outcomes?

Answer 1